1. Field of the Invention
The present invention relates to a rechargeable type portable lighting device, and more particularly to a portable lighting device of the type, in which a rechargeable battery and other necessary parts are accommodated in the body thereof and in which a charging plug is fixed to protrude from the back or side thereof.
2. Background of the Invention
As the portable rechargeable lighting device of the aforementioned type, there has been disclosed in U.S. Pat. No. 3,233,091 a lighting device which has its charging plug fixedly protruding. The lighting device thus disclosed has defects that the prongs of the protruding charging plug obstruct handling of the device and that the plug may be broken by a foreign substance.
Therefore, there has been proposed in U.S. Pat. No. 3,441,730 a lighting device of the type, in which a charging plug is accommodated in the body thereof, when in the operation other than the charging operation, and can be drawn out by means of an interconnecting wire when in the charging operation. The lighting device thus proposed has defects that the pulling and storage of the wire is troublesome and that it is liable to be troubled due to the disconnection of the wire. There have also been proposed both a lighting device of the type, in which the charging plug is hinged to the body thereof such that it is swung to protrude when in the charging operation, a lighting device of the type, in which the charging plug is detachably attached to the body thereof such that its prongs are made to protrude when only in the charging operation. However, the former has a defect that the construction of the power supply portion including its charging plug becomes complex, whereas the latter has a defect that the charging plug has a fear of being lost.
Moreover, since the charging current to the rechargeable battery to be used in the rechargeable type portable lighting device of one of the aforementioned types is far lower than the discharging current to be supplied from the battery to a bulb or the like, the bulb or the like necessarily has to be extinguished when the charging operation is to be performed. Otherwise, the charging operation cannot be effected. Therefore, there have also conventionally been proposed both a lighting device (as is disclosed in U.S. Pat. No. 3,441,730) of the type, in which the lighting mode of the bulb or the like and the charging mode of the battery are interchanged by means of a manual type switch and a lighting device (as is disclosed in U.S. Pat. No. 3,223,091) of the type, in which the interchange is automatically controlled by means of an electric circuit. However, the former cannot be freed from the operating mistakes of the operator, whereas the latter is accompanied by the complex circuit construction.